/Engine/Source/Runtime/Engine/Classes/Animation/AnimInstance.h
Get ActiveFAnimMontageInstancefor given Montage asset. Will return NULL if Montage is not currently Active.
[FAnimMontageInstance](API\Runtime\Engine\Animation\FAnimMontageInstance) * GetActiveInstanceForMontage ( const [UAnimMontage](API\Runtime\Engine\Animation\UAnimMontage) * Montage ) const